Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits


Product details


Vin (Min) (V) 2.5 Vin (Max) (V) 5.5 Vout (Min) (V) 0.7 Vout (Max) (V) 3.3 Iout (Max) (A) 0.35 Iq (Typ) (mA) 0.015 Iq (Typ) (uA) 15 Switching frequency (Min) (kHz) 550 Switching frequency (Max) (kHz) 1300 Features Enable, Light Load Efficiency, Synchronous Rectification Operating temperature range (C) -40 to 85 Rating Catalog Regulated outputs (#) 1 open-in-new Find other Buck converters (integrated switch)

Package | Pins | Size

SOT-23 (DBV) 5 5 mm² 2.9 x 1.6 open-in-new Find other Buck converters (integrated switch)


  • Input Voltage Range: 2.5 V to 5.5 V
  • Adjustable Output Voltages (VOUT): 0.7 V to 2.5 V
  • Fixed Output Voltages: 1.2 V, 1.5 V, 1.6 V, 1.8 V, 1.875 V, 3.3V
  • 15-µA Typical Quiescent Current
  • 350-mA Maximum Load Capability
  • 1-MHz PWM Fixed Switching Frequency (Typical)
  • Automatic PFM and PWM Mode Switching
  • Low Dropout Operation – 100% Duty Cycle Mode
  • Internal Synchronous Rectification for High Efficiency
  • Internal Soft Start
  • 0.1-µA Typical Shutdown Current
  • Current Overload Protection
  • Operates from a Single Li-Ion Cell or Three-Cell NiMH/NiCd Batteries
  • Only Three Tiny Surface-Mount External Components Required (One Inductor, Two Ceramic Capacitors)
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The LM3670 step-down DC-DC converter is optimized for powering ultralow voltage circuits from a single Li-Ion cell or three-cell NiMH/NiCd batteries. It provides up to 350-mA load current, over an input voltage range from 2.5 V to 5.5 V. There are several different fixed voltage output options available as well as an adjustable output voltage version.

The device offers superior features and performance for mobile phones and similar portable applications with complex power management systems. Automatic intelligent switching between pulse width modulation (PWM) low-noise and pulse frequency modulation (PFM) low-current mode offers improved system control. During full-power operation, a fixed-frequency 1-MHz (typical) PWM mode drives loads from approximately 70 mA to 350 mA maximum, with up to 95% efficiency. Hysteretic PFM mode extends the battery life through reduction of the quiescent current to 15 µA (typical) during light current loads and system standby. Internal synchronous rectification provides high efficiency (90% to 95% typical at loads between 1 mA and 100 mA). In shutdown mode (enable (EN) pin pulled low) the device turns off and reduces battery consumption to 0.1 µA (typical).

The LM3670 is available in a 5-pin SOT-23 package. A high switching frequency (1 MHz typical) allows use of tiny surface-mount components. Only three external surface-mount components, an inductor and two ceramic capacitors, are required.

For all available packages, see the orderable addendum at the end of the data sheet.

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Technical documentation

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Type Title Date
* Datasheet LM3670 Miniature Step-Down DC-DC Converter for Ultralow Voltage Circuits datasheet (Rev. F) Feb. 18, 2016
Technical articles Minimize the impact of the MLCC shortage on your power application Mar. 29, 2019
Selection guides Power Management Guide 2018 (Rev. R) Jun. 25, 2018
Application notes A Topical Index of TI Low Power Buck DC/DC Application Notes Jan. 17, 2018
User guides AN-1348 LM3670 Evaluation Board (Rev. D) Apr. 30, 2013

Design & development

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Hardware development

document-generic User guide

The LM3670 evaluation board is a working demonstration of a step down DC-DC converter. The application note contains information about the evaluation board. The LM3670 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell or 3 cell NiMH/NiCd (...)

  • Vout = adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875, 2.5, 3.3V
  • 2.5V less than or equal to Vin less than or equal to 5.5V
  • 1.5 microA typical quiescent current
  • 350 mA maximum load capability
  • 1 MHz PWM fixed switching frequency (typ.)
  • Automatic PFM/PWM mode switching
  • Available in fixed output voltages as well (...)

The 1280x800 LCD Display Accessory Kit is an add-on accessory for the AM65x IDK (TMDX654IDKEVM) to add touch and display functions for the evaluation of HMI, industrial PC, and other use cases requiring display. The 1280x800 LCD Display Accessory Kit comes bundled with the AM65x EVM (TMDX654GPEVM (...)


10.1" LCD screen (1280 x 800)

Design tools & simulation

PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)

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SOT-23 (DBV) 5 View options

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